The latest NAB Radio Show has come and gone, and there was little news about the HD Radio system other than the addition of new automobile makes and models to the company’s roster (including some GM models that had dropped HD last year). Not totally surprising considering that iBiquity’s just been acquired, and I’m sure the folks there and at new parent-company DTS were pretty preoccupied over the last couple of months with the deal.

But I did stumble across some interesting observations online that suggest there’s no rekindled love affair between HD and the industry just yet. In fact, folks still seem to be coming to grips with the fact that the technology still exists. The first is from Art Stone, the proprietor of Streaming Radio Guide. He scraped iBiquity’s directory of HD-enabled stations and crunched the numbers. iBiquity lists 3,818 “current HD based broadcast Channels.” This number counts all HD program streams, including HD-2/3/4 streams, and includes international broadcast licensees.

Of the total, 1,835 U.S. FM stations (17%) have licensed HD technology, as well as 214 AM radio stations (4%). Stone is correct to note that iBiquity’s list includes all stations that have licensed the technology, not a list of those actively using it. This is especially true with HD-AM, where a significant number of licensees have abandoned it.

Of all the HD Radio program streams available (including the HD-2/3/4 channels), 1,067 are listed as “independent,” while iHeartMedia gets credit for 863. A distant third in the stream-count is “Public Colleges and Universities” with 356. Stone suggests that “The HDradio list seems designed to make it hard to see the big picture. Keep in mind, they are not advertising streams. Their focus is to draw listeners to radio stations that bought their technology.”

Over on the Harker Research blog they’re wondering if Nielsen has something to do with HD’s ongoing malaise. They note that in order to make HD signals “fit” onto the AM and FM bands, “the digital channels are highly compressed using a proprietary algorithm that removes a great deal of content. In this regard, HD radio is like a low quality MP3 copy of a song.”

Long story short, by removing so much of the program audio there is not much left to insert Nielsen’s ratings watermark for pickup by Portable People Meter (PPM) ratings devices. According to Harker, “HD radio turns highly encodable analog content into unencodable digital content.” And while the HD system “has issues that go well beyond algorithms, but the medium shouldn’t be further punished because of Nielsen’s inability to accurately measure its audience.” More details on the finer points of HD’s proprietary encoding algorithm and how this complicates the process are reportedly forthcoming.

I get the sense that both Stone and Harker would like to be supportive of the technology, but they’ve found indicators to criticize that exist conveniently outside the HD system itself. The problem isn’t that iBiquity makes its HD station-directory hard to navigate, it’s the fact that fewer than one in five U.S. radio stations have adopted the technology and are doing something notably constructive with it. Similarly, the problem isn’t that Nielsen’s PPM encoding system doesn’t work well with HD transmissions, it’s the system’s own audio codec that shreds program material to the point of being nearly incompatible with PPM.

These are flaws inherent to HD’s design. It’s too early in the DTS acquisition/integration process to see if the system’s new owners will address these issues, but they’re not going to go away on their own.